I recently came home to find that my toilet was overflowing and that
the Torbeck bottom entry valve was not turning the water off when the
cistern was full. I fiddled with it but could not even understand how
it works. We later discovered that there had been a pressure surge and
all the water was turned off in the village for the next few hours (not
sure if this is relevant?).
I purchased the same valve but it does not work either - can anyone
help with a suggestion?

I had a torbeck valve fail completely and without warning when I had a
5th floor London flat and worked away during the week. Came home to
find the overflow literaly pouring onto the walkway. Never used one
since.

On 2006-09-15 14:32:17 +0100, said:

I recently came home to find that my toilet was overflowing and that
the Torbeck bottom entry valve was not turning the water off when the
cistern was full. I fiddled with it but could not even understand how
it works. We later discovered that there had been a pressure surge and
all the water was turned off in the village for the next few hours (not
sure if this is relevant?).
I purchased the same valve but it does not work either - can anyone
help with a suggestion?

They are an equilibrium valve.

The old fashioned Portsmouth ball valve closes off the main water jet
by brute force of a pad pushed over it as float rises. They are
relatively reliable but noisy.

If you take the Torbeck apart, you will find a black diaphragm with a
small offset hole. This fits over a needle projecting from the rear
body of the valve. Some older models had a little captive plastic peg
in the hole. The purpose of this is to allow a tiny flow of water
from the rear chamber to the front one.

On the front cap, there is another small hole which allows water to
leave the front chamber into the cistern. Notice that on the float
arm, there is a little pad which covers this hole when the float rises.

When the float is down, the water pressure forces the diaphragm forward
allowing flow into the cistern. The needle valve at the diaphragm
limits the flow through that path such that the pressure in the front
chamber is lower than the back one because of the escape of water
through the front pin hole.

WHen the float rises and the front hole is finally covered, the
pressure in the fron chamber becomes equal to that of the rear chamber.
The design of the diaphragm is such that under these conditions it
is slightly springy towards the back and shuts off the main flow of
water. It is arranged that this is done quite gently. Because of the
pressure equilibrium not a lot of force is required, unlike the
Portsmouth valve.

There are a couple of problem areas. The first is that the mains
pressure is too high - often there is water hammer as well. This can
be addressed by fitting the HP flow restrictor.

The other is that crud can be caught in either of the small holes.
This can be cleared with a piece of very fine fuse wire (not a needle).
Other than that, I would look for a manufacturing defect. You can
check whether the flow from the small hole at the front stops when the
arm is lifted. If it doesn't, thn the valve won't close

In article .com,
wrote:
I recently came home to find that my toilet was overflowing and that
the Torbeck bottom entry valve was not turning the water off when the
cistern was full. I fiddled with it but could not even understand how
it works. We later discovered that there had been a pressure surge and
all the water was turned off in the village for the next few hours (not
sure if this is relevant?).
I purchased the same valve but it does not work either - can anyone
help with a suggestion?

It's usually crud that stops them working. But a new one should have been
ok - unless there was a lot of crud in the pipe.

--
*Lottery: A tax on people who are bad at math.

Dave Plowman London SW
To e-mail, change noise into sound.

The message
from Andy Hall contains these words:

The old fashioned Portsmouth ball valve closes off the main water jet
by brute force of a pad pushed over it as float rises. They are
relatively reliable but noisy.

They also shut off gently, which can be an advantage if you can't be
arsed to take the whole house apart to find the loose pipe that rattles
every time the valve shuts.

--
Skipweasel
Pay no attention to that man behind the curtain.

Dave Plowman (News) wrote:

It's usually crud that stops them working.

Where did the crud come from ? Could the "pressure surge" have been
related to a crud-dislodging incident ?

My parents live close (few hundred yards) to a rural water treatment
works and sandbed filters. Until they installed large filters of their
own, they were continually plagued with sand in the water. Washing
machine valve seats wore out in no time, and Torbecks were certainly a
non-no.

But a new one should have been
ok - unless there was a lot of crud in the pipe.

New Torbecks usually fail because they didn't have the right restrictor
installed.

In article .com,
wrote:
It's usually crud that stops them working.

Where did the crud come from ?

Usually the minerals in hard water. Or at least in my case.

Could the "pressure surge" have been related to a crud-dislodging
incident ?

Dunno.

My parents live close (few hundred yards) to a rural water treatment
works and sandbed filters. Until they installed large filters of their
own, they were continually plagued with sand in the water. Washing
machine valve seats wore out in no time, and Torbecks were certainly a
non-no.

Any compensation? You'd not normally expect chunks of anything coming down
the mains.

But a new one should have been
ok - unless there was a lot of crud in the pipe.

New Torbecks usually fail because they didn't have the right restrictor
installed.

Ah. Does that do them permanent damage?

--
*Change is inevitable ... except from vending machines *

Dave Plowman London SW
To e-mail, change noise into sound.